Game is solid as a whole. Aside from keys and other items being blocked by blocks that cannot be destroyed everything seems fine.
Balance wise:
I hate the spikes. Hard to see on some floors and are not removed unlike other traps.
Chargers are simply too strong. Their projectiles are almost instant and fire too rapidly and they are not frail enough to be considered glass cannons.
I died on the 5/5 floor final boss because it's projectiles simply didn't give gaps.
I HATE how I pick up items I don't need/ can't use.
Unfortunately, while the game itself is fine after playing 68 minutes and dieing to the final floor boss I feel burnt out. The story hinted that I would get stronger over time, but after dying I don't grasp how I became stronger for my next game through. I feel like the floors are too long, or that there isn't enough variety, or both. I lack a "hook" to get me drawn in and that's ok this isn't exactly my forte.
A few things:
Chargers will be looked at; however, their weaponry is not likely to change. Aside from their overblown HP (which is the part that needs looking at), they are functioning as intended. Those things they "fire" arent meant to be projectiles, they're more like damaging tendrils. If you've met up with the Nanite Squid (Chris's design), it's pretty much the same concept. I might slow the things down slightly though. But mostly, chargers are about the player reacting; not dodging. Typically, either firing a single monstrous burst at them to take them down in one shot, or, using sprint while firing back at them is the keys to defeating them.
The "hook" of a game like this isnt really about story or even progression; it tends to be about replay value, each individual run. Oh, there will be a story I'm sure, this being Arcen (though I frankly havent the foggiest clue what it is), but it's unlikely to be the real draw of it. Hell, the sorts of games that I myself am inspired by in my enemy/boss designs often literally dont even HAVE one (and I tend to be very grateful for this).
For progression, originally there was the AP system; this was removed by Chris for a large variety of reasons. Now, there will be traditional unlocks, which seem like they're very close to how the original AVWW did it. Is the description of the game still mentioning that system? If so, that needs to be addressed.
For floor 5's boss, ahhh... well, this is one of my designs we're talking about, and as most have discovered by this point, I'm not good at keeping things easy or holding back; far as I"m concerned, it already IS easy. The current version of the Warden is actually going to be the Hard mode version, since I went overboard with it (again). The altered Normal version simply hasnt been made yet. That being said, there is now a video in the Centrifuge/Periphery/Aberration topic (3rd page, I think) showing a full defeat of the thing and how to deal with it.
Keys and things are never blocked by things that cant be destroyed. Havent encountered that even once. The issue is that I dont think the game points out HOW to destroy those. You need missiles for the type of block you're thinking of. The tutorials werent ready yet for the longest time. Actually come to think of it, I dont actually know if they're up yet. They might be.
I'm not sure about the idea of becoming stronger for the next game.... that mighta been with the AP system. This type of game is about becoming stronger DURING a run. That might have been part of why the AP system was removed, I'm really not sure. Chris would have more to say about that.
Spikes: Yes, annoying, arent they? I'm glad you brought that up, I've been meaning to talk with Chris and the others about that, but keep forgetting. I do think they should vanish in combat rooms when those rooms are clear or if a generator is destroyed. Also their hitboxes seem REALLY weird.